TABLE OF CONTENTS In previous chapters, we discussed in detail the most typical and frequent factors limiting EMF measurement accuracy. They resulted mainly from the type of antenna applied in an EMF probe, its size, and mutual couplings between the antenna and a radiation source. In this chapter we will briefly discuss the influence of thermal drift upon the probe parameters, the role of its dynamic characteristics, and the deformation of the measured field by a person performing the measurements, the meter, resonant phenomena, and others.
The meter parameters are a function of temperature as well because of the strong thermal dependence of semiconductor device parameters applied in EMF probes mainly for the measured signal detection (diode, magneto-diode, Hall-cell, thermocouple). The thermal instability may be a source of remarkable measurement error. The errors (as the deterministic ones) may be limited to a considerable degree by the use of appropriate correction factors (calculated or measured) or by the choice of measurement conditions that would assure error minimization. Although measuring device manufacturers do their best to obtain the most acceptable parameters (including thermal parameters) for their tool, more and more extremely simplified devices are appearing on the market. These devices can assure a comparatively low price but sometimes it is at the expense of quality. In order to enable a user to evaluate these devices under the influence of extreme conditions, the role of quality (or lack thereof) must be examined.
The subject of our analysis will be...
